Final answer:
The statement that mules are not considered a distinct species because their chromosomes are not homologous is a. true. Mules have an odd number of chromosomes, preventing proper pairing and fertility, disqualifying them as a distinct species.
Step-by-step explanation:
The statement 'Mules are not considered a distinct species because their chromosomes are not homologous' is TRUE. A mule is the offspring of a male donkey (jack) and a female horse (mare), which means it inherits 62 chromosomes from the horse and 63 from the donkey, resulting in an odd number of chromosomes, 63. This odd number prevents the chromosomes from pairing up properly to form homologous pairs, which is necessary for proper meiosis and subsequent reproduction. Since mules typically cannot reproduce, they are not considered a distinct species as they do not meet the biological definition of a species, which includes the ability to produce fertile offspring.
However, mules are produced by mating a male donkey (which has 62 chromosomes) with a female horse (which has 64 chromosomes), resulting in an offspring with 63 chromosomes. The uneven number of chromosomes prevents proper pairing and recombination of homologous chromosomes, making mules infertile and unable to produce viable offspring.